Lubricating device for sewing machines



' LUBRICATING'DEVICE Fon sEwING MACHINES x Filed Dec. 6, 1938 2 Smets-sheet 2 a a@ k f i Patented July 3, 194i Walter Myers, Bridgeport, Conn., assignor to The Singer Manufacturing Company, Elizabeth, N. J., a corporation of New Jersey Application December 6, 1938, Serial No. 244,145

12 Claims. (Cl. 112-256) This invention relat, to sewing machines and has for its primaryV object to provide improved means for properly lubricating the thread-case raceway of a sewing machine loop-taker to meet requirements at different speeds of oper-ation of the sewing machine. l

A further object of the invention is to provide the work-arm class of sewing machine with 1ubricating means for work-feeding and loop-taker actuating mechanisms constructed and arranged within the work-arm to safeguard the work and stitching threads from becoming soiled by lubricant.

The invention consists in the devices, combinations and arrangements of parts hereinafter described in connection with the accompanying drawings which illustrate a preferred embodiment of the invention and in which;

Fig. 1 represents a top plan view of the .workarm of a feed-oii-arm sewing machine having the work-arm cover-plate removed. Fig. 2 represents a vertical section longitudinally of the work-arm with its cover-plate applied thereto, the section being taken substantially on the line 2-2 of Fig. 1. Fig. 3 represents an enlarged transverse section of the work-arm on substantially the line 3-3 of Fig. 1, with the addition of theiwork-arm cover-plate. Fig. 4 represents' Fig. 5 represents an enlarged detail view, partly in perspective and partly in section, of the looptaker shaft bearing-bracket and the oil-metering device therein. Fig. 6 represents a vertical section of the portion of the work-arm partitionwall containing the oil-trap, the section being taken longitudinally of the work-arm.

The present invention has been embodied in a feed-off-arm zigzag stitching machine of which the frame corresponds, in general, to that disclosed in my prior U. S. Patent No. 1,999,978,

April 30, 1935. As illustrated in the present drawings, the frame referred to includes a horizontally disposed carrier-arm I from which ex'- tends a hollow or trough-shaped work-arm 2 free A at its end opposite to the carrier-arm I.

, the bevel-gear- 1 is a smaller bevel-gear 8 secured upon one end of a shaft-section 9 of a seti.

tional loop-taker actuating shaft extending` lengthwise of the work-arm, the gears 1 and l being proportioned so that the shaft-section 9 rotates twice for each rotation of the actuating shaft 5. The shaft-section 9 is rotatably journaled in a bushing I0 fixed in a suitably apertured bearing-block II secured by screws, as I2, upon a lug I3 rising from the bottom wall of the work-arm 2 at the carrier-arm end thereof.

At its end opposite the bevel-gear 8, the shaftsection 9 has a suitably socketed head It connected by a universal joint with one end of a shaft-link I5, of which the opposite end is similarly connected with a socketed head I6 carried by a reduced end of a loop-taker carrying shaftsection Il. The shaft-section Il is rotatably journaled in a bushing I8` secured, by a screw I9, for endwise adjustment in `a suitably apertured work-arm partition-wall 20, one end of said bushing abutting the shaft-section head I6.

Secured upon the end of the shaft-section I1, to abut the other ,end of the bushing I8. is the hub 2| of a horizontal-axis loop-taker 22 of the Y rotary-hook type. The loop-taker 22 has a cup- 4 shaped body internally provided with theusual ancarrier 23 is restrained against rotation with the loop-taker by -a bent arm 24 secured upon a side wall of the Work-,arm 2. The loop-taker 22 cooperates with a vertically reciprocatory and laterally vibratory needle 25 in the formation of zigzag lock-stitches, said needle operating through a slotted work-supporting throat-plate 26 and being actuated in any usual or suitable manner so that successive work-penetrating movements thereof are performed in separate paths spaced transversely of the length of the work-arm 2.

Itwill be noted that by endwise adjustment of the bushing yI8 in the partition-wall 20, the loop-taker 22 may be conveniently set for proper cooperation with the needle 25, without disconnecting the loop-taker actuating connections, the universal-joint connections between the shaftsections permitting of the requisite movement of the .bushing I8. It will further be noted from Fig. 2 of the drawings that the'rotation axis of the loop-taker shaft-section I'l is higher than that of the shaft-section 9, whereby the workarm 2 may be tapered toward its free end so as to -be of minimum cross-section `at the stitching point.

escasos The throat-plate 2t is suitably secured upon the work-erm in abutting relation with o, wort:-

arm cover-plate 21 secured byscrews, as 2t, i

upon the upper edges oi' the work-arm, e gasket 2b being preferably interposed between seid werbarm. and the cover-plate and throat-plate to provide an oil-tight joint therebetween.1 The partition-well 2d rises from the bottom wall ci the work-arm adjacent the free end thereof and extends entirely across the work-erm rwicltlrwise thereof, the upper face of said partition wall being substantially ush with the upper side edges of the work-erm, whereby thegaslret 2t seais said upper face of the partition-wall 2li. It will therefore be understood thet the partition-wall 2t divides the hollow work-arm into an oil-splash actuating mechanism containing compartment end a sewing-mechanism containing compartment.

The work is advanced lengthwise of and toward the free end oi the work-arm 2 by a feeddog 30 which operates through suitable slots in the throat-plate 26 and is opposed by a presserfoot 3i. The feed-dog dii overhangs the looptaker 22 at the free end of the work-arm 2 and is secured by screws SZ upon one end of a feedbar 33. The feed-har 3? extends lengthwise of und withintbe work-arm 2 adjacent one side welll thereof, said feed-bar being slidingly guided by the wells of a. slot 3E in the partition-wall 2d. The feed-ber 33 is supported for rocking and endwise sliding movements within -an upwardly open guide-slot 35 provided in en extension 28 oi the partition-wall Eli, said feed-bar having en elongated aperture 36 to slidingly receive a pivotblock 3d upon the eccentric end of an adjustable iulorum-pin tisecured, in set position in the wall-extension 2li', bye. screw 3b. 'The setscrew it is preferably accessible from the top of the work-arm by the provision ci a suitable aperture in the work-arm cover-plate 21 and its underlying gasket Z9, said gasket by its 'engagement with the top face of the partition-wall err-- tension l2h' serving to prevent oil-leakage through said apertures. The rul'crum-pin S1 extends horizontally scross the work-arm 2 and through s. bearing-boss 3Q in the work-arm'side wall opposite to the feed-bar side wall, so as to be conveniently accessible for adjustment.

At its end opposite to the feed-dog 36, the feedbar Si has a laterally odset fork l embracing a. feed-,lift eccentric il carried by the rotary shaft E, said eccentric imparting rocking movements to said feed-bar about the fulcrum-pin 31, and thereby rising and falling movements to the feed-dog 3u. Adjacent the eccentric di, the shaft ii carries an adjustable feed-advance eccentric t2 which is constructed and may be adjusted substantially in accordance with the dis tomatically lubricating the actuating mechanism above described and, more particularly, for lubricating the thread-case raceway in the looptalrer. As illustrated in Fig. 2 of the drawings, the inner face 4t of the bottom Wall of the workthe bearing-supporting'lug I3, and said lug is spaced from one side wall of the work-arm to permit lubricant to drain into a reservoir il' provided at the junction of the carrier-arm i and work-arm 2. The feed-forks Ill, 4t and the looptaker shaft driving gearing dip into said reservoir t1.

Depending vertically from the work-arm cover-plate 21 to extend into the reservoir 41, is a filling-tube' i8 having at its upper end a shouldered flange tt tightly fitting an aperture in said cover-plate and provided in its upper face with n recess E0. Removably disposed within the iiliing-tube 8- is a measuring-gauge in the form of a shouldered rod tl! having a reduced and attened lower end, and an enlarged shank 5i' which slidingly fits the bore of said iilling tube.

The rod-shank 5I' yterminates at its upper end in aiange E2 seated upon the tube-flange t9 in the recess 5G thereof, the upper end ci the `rod 5i being formed to provide a knob 53 by means o which the rod may be withdrawn to ascertain the depth of the lubricant within the reservoir 41 and to supply lubricant through the tube 48. The knob 53 is preferably disposed substantially iiush with or slightly below the upper face of the cover-plate 21 and the filling-tube 48 is preferably provided, between its ends, with en air-vent aperture 54.

In the operation of the sewing machine, the

sctuating mechanism disposed Within the reservoir il acts to agitatov the lubricant-supply within said reservoir, thereby lubricating said actuating mechanism and creating a lubricant mist within the work-arm serving to lubricate the feed-bar fulcruin, the connections between the sections of the loop-taker shaft and also the bearing for the shaft-section 9L The partitionwell 20 and the extension 2li thereof, together with the gasket-.ed cover-plate 21 overlying said wail, serve to baille passage of the lubricant to the free end of the work-arm. The wall 20 is chambered to provide an oil-trap 55 between the Wall-slot 34 and the wall-extension slot 35, said oil-trap serving to collect lubricant seeping between the gasket 23 and the feed-bar adjacent the fulcrum-sxis oi.' the latter. The lubricant collected in the oil-trap 55 is free to drain back into the work-arm through an aperture i8 provided in the extension-wall 20.

suitably attached to the under side of the work-arm cover-plate 21 is a U-shaped conduit 51, of which one end terminates adjacent the actuating mechanism within the reservoir t1, whereby lubricant agitated by said-mechanism. is also supplied to said end of the conduit 51; The conduit 51 declines toward its other end which extends freely through a. slot 58 in the partition-well 20 to terminate in an oil-pocket 5S formed by an upwardly open annular recess in the partition-wall 20. The bottom. of the oilpoclret 53 is preferably disposed below the level of the bottom of the slot 58 which opens into seid oil-pocket. Therefore, while the slot I58 constitutes an oil-discharge port for excess oil delivered by the conduit 51 to the oil-pocket 59, a residue of oil below the level of the slot 58 will be retained by the oil-pocket and serves as an sir-seal ior a countersunir aperture Ell in the bottom wall of the oil-pocket 5S. The oil-pocket aperture Sil is connected by a duct 6i in the bushing it with an annuler recess 62 in the shaft-bearing face of said bushing.

Disposed upon the bottom wall of the oilexcess lubricant into the reservoir 41.v

pocket 59 is an oil-conductor of variable porosity and preferably in the form of a compressible'disk 63 of felt or like lubricant-conducting material, and overlying said disk 63 is a circular flange 64 of a screw 65 which is threaded into an apertured boss 66 depending from the under side of the cover-plate 21. The threaded aperture of the boss 66 preferably terminates in the upperface of the cover-plate 21, whereby the slotted upper end of the screw 65 is conveniently accessible. While the flange 64 is diametrically' smaller than the oil-pocket 59 and is preferably diametri/:ally smaller than the disk 63, whereby the disk 63 is partly exposed to the oil delivered through the conduit 51, said flange 64 overlies that portion of the disk 63 above and directly adjacent the oil-pocket-aperture 60. By adjustment of the screw 65, the pressure of the flange 64 upon the oil-conducting disk 63 to compress said disk may be regulated to control the delivery of oil by the disk 63 to the bushing recess62. The oil-metering device described therefore provides for regulating the quantity of oil supplied to the bushing-recess 62, thereby to meet different-requirements and more particularly at different speeds of operation of the sewing machine.

The loop-taker shaft-section I'1 has a longitudinal bore 61 and a diametral aperture 68 con- .nected with one end of said bore within the bushing recess 62. The other end of the shaftbore 61 is connected in the usual manner by a radial-bore 69 in the loop-taker 22 with the thread-case raceway in said loop-taker.

From the foregoing description it will be understood that, in the operation of the machine, lubricant in the reservoir 41 will be splashed into the'end of the conduit 51 adjacent the actuating mechanism within said reservoir and that the conduit 51 delivers the lubricant to the oilpocket 59. The oil-metering device within the oil-pocket 59 provides for regulating the quantity of oil delivered tothe loop-taker raceway, the excess lubricant delivered to the oil-pocket 59v draining therefrom into the work-arm 2 through the partition-wall slot 58. 'I'he inclined provides for emcient and regulatable lubrication of the loop-taker raceway.

Having thus set forth the nature of the invention, what'I claim herein isz' 1. A sewing machine having a rotary looptaker provided with a thread-case raceway and with a radial bore connected with said raceway,4 a rotary loop-taker carrying shaft provided with a longitudinal bore connected with said lradial bore of the loop-taker, said shaft having a radial aperture connected with said shaft bore and substantially shorter than the length of the looptaker bore, an oil-pocket having a bottom-wallA aperture connected with the radial aperture of said shaft, said oil-pocket having an excess-oil discharging port above the level of said bottomwall aperture whereby an air-sealing residue of oil is disposed in said pocket, means for controlling the flowof oil through the bottom-wall aperture of said pocket, and means effective [during the operation of the machine for supplying oil to said pocket.

2.`Al sewing machine having a rotary looptakerprovided with athread-case raceway, a rotary loop-taker carrying shaft provided with a longitudinal bore having lubricant-conducting connections with said raceway, an oil-pocket having an aperture connected with the bore of said shaft, said oil-pocket having an excess-oil disbottom wall 46 of the work-arm 2 drains the It will furthermore be understood that oil seepage along the shaft-bearing face of the bushing I8 provides for lubricating the shaft-section I1.

Any lubricant escaping from the end of the bushing adjacent the loop-taker is collected in a recess 10 formed in a gasketed guard-plate 1l embracing the hub 2| of the loop-taker and secured by screws 12 to the wall 20. From the recess 10, the lubricant drains through a duct 13, in the partition-wall 20, into the open portion of the work-arm and into the reservoir 41.

As the radial bore 69 in the loop-taker 22 is longer than the radial length of the loop-taker shaft aperture 6B, the centrifugal force developed at the raceway end of the loop-taker bore 69 is greater than the centrifugal force opposing entrance of oil into said shaft-aperture 68. Consequently, the tendency is to developa suction of oil into the shaft-aperture 68. Owing to the airseal afforded by the oil-residue in the bottom of the oil-pocket 59, the formation of obstructing air-bubbles in the oil-conducting connections between said pocket and the loop-taker raceway is eliminated, it being understood that the continuous delivery of oil to the oil-pocket 59 during the operation of the machine, together with the oil-metering device described, not only insures a constant oil-residue in said oil-pocket 59, but also charging port above the level of said aperture, an oil-conductor of variable'rporosity-v disposed in said oil-pocket to overlie said aperture, means for supplying lubricant to said oil-pocket, and manually adjustable means for regulating the porosity of said oil-conductor.

3. A sewing machine having a frameincluding a hollow work-arm internally provided with a transverse partition-wall rising from the bottom wall and extending from one to the other side wall'of said work-arm, Asaid partition-wall ,being provided lengthwise of said-work-arm with a shaft-bearing aperture and with a slot enlarged between the ends thereof to'provide an oil-trap in said partition-wall, a rotary loop-taker shaft journaled in said bearing-aperture, a loop- 1 taker carried by said shaft at one side of said partition-wall, a feed-bar extending through and 'slidingly disposed in said partition-wall slot, a

feed-dog carried by said feed-bar at the looptaker side of said partition-wall, a lubricant-reservoir in said frame at the opposite side of said partition-wall, and mechanism including a member dipping into said reservoir for rotating said loop-taker shaft and for actuating said feed-bar to vimpart work-feeding movements to said feeddog lengthwise of said work-arm.

4. A sewing machine having a rotary looptaker provided with a thread-case raceway, a lubricant-supply reservoir, a lubricant-pocket disposed between said reservoir and said raceway and provided with excess-lubricant discharge means, a lubricant-metering device disposed in said lubricant-pocket below the level of said discharge means, means for supplying a flood of lubricant from said reservoir to said lubricantpocket, and suction-inducing means for drawingY lubricant through said metering device and delivering it to said raceway.

5. A sewing machine having a rotary looptaker provided with a thread-case raceway, a lubricant-supply reservoir, a lubricant-pocket disposed between'said reservoir and said Araceway and provided with excess-lubricant discharge means, a lubricant-metering device disposed in said lubricant-pocket below the level of said discharge means, means for supplying a ilood of lubricant from said reservoir to said lubricant-pocket, suction-inducing means for drawing lubricant through said metering device and delivering it to said -raceway, and means for conducting away from said lubricant-pocket an excess of lubricant delivered to said metering device.

6. A` sewing machine having a rotary looptaker provided with a thread-case raceway, a

lubricant-supply reservoir, a lubricant-pocket disposed between said reservoir and said raceway and provided with excess-lubricant discharge means, a lubricant-metering device disposed in said lubricant-pocket below the level of said dis--` disposed between said reservoir and said raceway and provided with excess-lubricant discharge means, a lubricant-metering device disposed in said lubricant-pocket below the level of said discharge lmeans, means including an element operated by a moving part of the machine for sup-` plying an excess of lubricant to said metering device from Asaid reservoir, suction-inducing means for drawing lubricant through said metering device and delivering'it to said raceway, and means for returning tosaid reservoir excesslubricant delivered to said metering device.

8. A sewing machine having a rotary 4looptaker provided with a thread-case raceway and with a radial duct connected with said raceway,

with excess lubricant discharge means, a compressible lubricant-penetrant metering element disposed in said .lubricant-pocket below the level of said discharge means, means for supplying lubricant from said reservoir to said metering element, suction-inducing means for drawing lubricant through said metering element and delivering-it to said racewayI and manually adjustable means accessible irom above said work-support for regulating the degree of compression of said metering element. i

10. A sewing machine having a work-support, a rotary loop-taker :disposed below said worksupport and provided with a thread-case raceway, ar lubricant-supply reservoir, a lubricantpocket disposed below said work-support and having lubricant-conducting connections with said raceway, a compressible lubricant-penetrant meteringv element disposed in said lubricantpocket, a metering-element regulating screw threaded into said Work-support, said screw having a flanged lower e'nd in engagement with said metering element and having its upper end aceessibie fromV above said work-support, and

a rotary loop-taker carrying shaft provided with a longitudinal bore connected with said radial duct of the loop-taker, said shaft having a radial aperture connected with said shaft bore and substantially shorter than the length of the looptaker duct, a lubricant-supply reservoir, a lubricant-pocket disposed between said reservoir and said radial duct of the loop-taker shaft, said pocket being provided with excess-lubricant disv charge means, a. lubricant-metering device disposed in said lubricant-pocket below the level of said discharge means, 'means rendered effective by a moving part of the machinev for delivering lubricant from said reservoir to said metering device, means. for conducting lubricant delivered by said metering device to the radial duct of said loop-taker shafnmanually adjustable means for regulating the lubricant-delivering capacity of said metering-device, and means for returning to said reservoir excess-lubricant discharged from said pocket. f

9. A sewing machine having a work-support, c. rotary loop-taker disposed below said work-support and provided with a thread-case racewama lubricant-supply reservoir, a lubricant-pocket disposed below said work-support and provided means including an element operated by a moving part of the machine for supplying lubricant from said. reservoir to said pocket.

11.(In a sewing machinel having a frame including a hollow work-arm free at one end thereof, a rotary loop-taker` disposed within said workarm at the free end thereof and having a threadcase raceway, a rotary loop-taker carrying shaft provided with a longitudinal bore terminating at one end in a radialgshaft-apertureand having lubricant-conductingconnections at its other end with said raceway, a` lubricant-reservoir within.i

the end portion of said work-arm opposite to the free end thereof, a lubricant-pocket disposed within said work-arm having excess lubricantdischarge means and having lubricant-conducting connections withA said radial shaft-aperture, a manually regulatable lubricant-metering device in said pocket `below the level of said discharge means, a lubricant-conduit extending lengthwise of said work-arm disposed to discharge a ood of lubricant in said pocket, and mechanism adapted to dip into lubricant in. saidreservoir for supplying lubricant to` said conduit.

12. In a sewing machine having a frame including a hollow work-arm free at one end thereof, a cover-plate detachably lsecured upon said work-arm, a' rotary loop-taker disposed within said work-arm at the'free end thereof and having a thread-case raceway, a rotary loop-taker .carrying shaft provided with a longitudinal bore connected with said 'raceway, said shaft having ervoir to said conduit. 

